I must start with a little gloat to put this in perspective. For the
past year I have been scrounging parts for an engine driven 40 gph
watermaker. So far I have a stainless Cat 241 pump, electric clutch,
over/underspeed switch, two new 40" membranes and pressure vessels,
supply and product flow meters, diverter solenoids, pressure switch,
digital pressure gauge and all the hoses, pre filters and fittings.
Total investment to date is $1,256.40

There is just one snag. The last part I need is the stainless steel
back pressure regulator to maintain a constant 800 psi in the membranes.
These things must be pretty rare because I have not been able to
scrounge one and the cheapest one I can find costs SIX HUNDRED
DOLLARS!!! That would be 30% of the total cost in one valve. Surely
there is another solution.

If any of you have an engine driven watermaker, would you please take a
look at your regulator and let me know what it says on the label?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Glenn-Have you tried Village Marine Tech...theirs is a fairly simple bp
reg....I can't imagine it being more than $150..

Regards-
Charlie

Thanks I will check it out. I did find a CAT 7070 stainless BP
regulator for $220.00.

Charlie J wrote:
Glenn-Have you tried Village Marine Tech...theirs is a fairly simple bp
reg....I can't imagine it being more than $150..

Regards-
Charlie




--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

I've just looked for the article I read when I was deciding on whether
to put a steam distiller or osmosis system into my house. I chose
steam distillation.

The article was NOT published by either camp of zealot salesman trying
to make the other guy's system look bad. It came from a medical
university. Sorry it's gone......

But, the gist of what I read about osmosis turned me off. The start
out just great on their $150 membranes, but they deteriorate rapidly
into 80% filter. What was the MOST disturbing was a medical report I
read about bacterial breakdown at the membrane.....

The membrane blocks bacteria, all of it or nearly all of it. However,
the bacteria piled up against the membrane are bombarded by the stuff
the membrane is filtering and soon BREAK UP into their TOXINS whos
molecules are SMALLER than the water molecules.....and pass THROUGH
the membrane into your side. This is bad, really bad.

It scared me away from osmosis, the holy grail of water filter plants.
It just makes sense.

My system here makes 12 gallons a day on 1200 watts of electricity.
There is a carbon prefilter to pull the organic chemicals out of the
water prior to the boiler, then another carbon post-filter on top of
my collection tanks to trap the benzene and the like out of the
condensed water that usually gives distilled water that metallic
taste. What comes out is really delicious and has a VERY high
resistance in the multigigohm range at 10KVDC, one of the best tests
of purity. Costs about 30c/gallon to make and there is little
recurring costs like expensive, hightech membranes, backflushing and
maintenance. My unit is porcelain and easily comes apart. Just a
flush to get the scale out that's flaked off the stainless element and
she's ready for more......



Larry W4CSC

"No, NO, Mr Spock! I said beam me down a WRENCH,
not a WENCH! KIRK OUT!"

Larry,

But you are not distilling from sea water are you? I suspect
that you'd have significantly more "scale" if you filled it up
with sea water and fired it up.

Don W.

Larry wrote:
snip

My system here makes 12 gallons a day on 1200 watts of electricity.
There is a carbon prefilter to pull the organic chemicals out of the
water prior to the boiler, then another carbon post-filter on top of
my collection tanks to trap the benzene and the like out of the
condensed water that usually gives distilled water that metallic
taste. What comes out is really delicious and has a VERY high
resistance in the multigigohm range at 10KVDC, one of the best tests
of purity. Costs about 30c/gallon to make and there is little
recurring costs like expensive, hightech membranes, backflushing and
maintenance. My unit is porcelain and easily comes apart. Just a
flush to get the scale out that's flaked off the stainless element and
she's ready for more......

Larry W4CSC

"No, NO, Mr Spock! I said beam me down a WRENCH,
not a WENCH! KIRK OUT!"

On Sun, 03 Aug 2003 17:04:21 GMT, "Don W."
wrote:

Larry,

But you are not distilling from sea water are you? I suspect
that you'd have significantly more "scale" if you filled it up
with sea water and fired it up.

Don W.

No, but the Navy has been for years...(c;

Point is lots of boaters think reverse osmosis is clean water because
it does take the salt out. But that disturbing report of the bacteria
breaking down against the membrane and the toxins they release passing
through into the drinking water SURE makes one think about drinking
it.....

I don't think they're replacing the membrane often enough in any boats
with these watermakers I know of.



Larry W4CSC

"No, NO, Mr Spock! I said beam me down a WRENCH,
not a WENCH! KIRK OUT!"

On Sun, 03 Aug 2003 13:05:44 -0400, Glenn Ashmore
wrote:

Most boats can't afford 100 amp hours a day just to make 12 gallons of
water.

What I can't figure out is why someone hasn't created a dry exhaust
stack distiller! All the heat you'd ever need is just dumped up the
stack on many nice boats that COULD be making clean water whenever the
engine was running....


Sea water membranes will not pass bacteria but certain viruses and any
chemical with a lower osmotic pressure will get through so post
treatment (charcoal, UV etc) is recommended. Also, water being the
universal solvent, RO water is acetic. So post treatment with lime can
be useful to raise the PH back to normal.

They're not passing the large bacteria. What they're passing is the
released toxins when the bacteria on the pressure side of the membrane
break down. The toxins are SMALLER than the membrane's threshold, so
pass right on through. Most interesting.

I know someone who got sick drinking a very-well-maintained reverse
osmosis system from seawater. He's a stickler for correctness. I
gave him this information and he said it sounded like what he had.

Your mileage may vary, but this is not rocket science.

It's not the Holy Grail, though.


Larry W4CSC

"No, NO, Mr Spock! I said beam me down a WRENCH,
not a WENCH! KIRK OUT!"

Jere Lull wrote in message ...
Larry wrote:

On Mon, 04 Aug 2003 05:02:15 GMT, Jere Lull wrote:



Is that 1200 watts over 24 hours? Or do you mean 1200 watt-hours?
Judging by how long it takes to boil a pot dry at home, I suspect the
prior, but even at 1200 watt-hours, that's somewhat over 100 AH per day
for merely 12 gallons. WAY expensive!



Yes... 1.2KWh/hour, about 10 cents per hour or 20 cents per gallon
from the power company.

Okay, taking that as a starting point, to get 12 gph (which is not
especially high output), the power requirements would be on the order of
30 KW/hr -- 2000+ amps at 12v; you'd want to go to higher voltages!
That's beyond most generators, or even primary power plants. Even our
home oil-fired furnace, rated for steam, might not be able to distill
THAT much water that quickly.

I've always wondered why there wasn't a distiller that ran off dry
stack heat, which would inundate the boat with fresh water, literally
for free on a cruising power boat with dry stacks. Navy distillers
make great water on ships.

Wouldn't work on our boat (20 HP Yanmar) or most engines I've seen up to
about 80 HP. In the few hours they run each day, there's just not that
much waste heat. The Navy isn't exactly known for efficient power
plants, and their ships are a bit bigger than what we cruise on.

I checked into the "evaporators" as they're called. They use engine
cooling water to distill seawater under vacuum. An electric motor/pump
generates the vacuum. It's not without faults however. The problem of
"carryover" in rough seas is always there. The electric motor is
pretty hefty (I forget exactly how hefty). There is a brochure at

http://www.beairdindustries.com/asse...rator_Book.pdf

I looked into the Maxim HJ3C which is the smallest at 2-8 GPH. The
price was *way* higher than RO, even without the other ancillary
equipment needed.

HV

On Mon, 04 Aug 2003 13:16:02 GMT, (Larry) wrote:

What I can't figure out is why someone hasn't created a dry exhaust
stack distiller! All the heat you'd ever need is just dumped up the
stack on many nice boats that COULD be making clean water whenever the
engine was running....

They used to make yacht size stills that ran on the waste heat from
the engine. They got more than a gallon of water per gallon of fuel
burned, so you carry fuel instead of water, and have more range.

Casady

On Wed, 07 Jul 2010 14:50:21 -0500, Richard Casady
wrote:

On Mon, 04 Aug 2003 13:16:02 GMT, (Larry) wrote:

What I can't figure out is why someone hasn't created a dry exhaust
stack distiller! All the heat you'd ever need is just dumped up the
stack on many nice boats that COULD be making clean water whenever the
engine was running....

They used to make yacht size stills that ran on the waste heat from
the engine. They got more than a gallon of water per gallon of fuel
burned, so you carry fuel instead of water, and have more range.

Casady

Did they run on heat alone or was there a vacuum pump involved? I once
maintained a system that, powered by a Perkins, used both.And, frankly
was an absolute ******* to keep running.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)